Bogus ligatures in OpenSymbol font

[Khaled Hosny]

While trying to fix a bug in OpenSymbol font, I found that it contains
some a GSUB table with some weird ligature entries, namely:

    period + period + period                               -> ellipsis
    integral + integral                                    -> double integral
    integral + integral + integral                         -> triple integral
    contour integral + contour integral                    -> surface integral
    contour integral + contour integral + contour integral -> volume integral

Not only they are wrong (OpenType features shouldn’t change the
underlying meaning of the text), I doubt they were ever used since we
didn’t apply ligatures in non-complex text until relatively recently
(and we still don’t apply them on Windows).

Anyone knows why those ligature are there, or should I assume that it
was just some oversight decades ago and drop them?

Regards,
Khaled